Hi Annie, 

Model Boats - no idea but i know a man who has - Slieve builds and races them.  No doubt he will respond when he gets a moment. 

To me it is about getting 'good enough'  results and KISS. I do not have to stand up an prove it beyond all reasonable doubt - balance of probability will do for me,

Regarding Arnes points and drawing above;  a few week ago in "Technical Illustrations", i posted a few photos of just that and yet a few more in my Members Profile - though i haven't  added comments to them yet. I was just doing some very quick mucking around, and will give some thought to Arne's suggestions.

I am playing with ideas in my head an hope to respond later this evening with a few workable ideas or at least partially addressing some of the points raised by David T and Arne K

But excellent response so far thanks to all. By throwing ideas around i am sure good things will emerge.

Ash

Frankly, I think there will be too many error sources here to warrant such a complicated test set-up that you describe. I agree with the points that David mentions, and really miss any indication of lift/drag ratio, which is a key parameter when it comes to sailing up-wind.

I suggest you rather try a simpler test, at least to begin with. All you then need is

• the panels you already have made (battens held apart with thin sticks at both ends),

• plus a video camera on a tripod.

The (transparent or transluctant) test panels must be generously tufted on the low-pressure side – which here will be on the upper side.

In a half-decent, but not too strong wind, you will be able to hand-fly the panels like here, one at the time. The camera, positioned at 10m distance, perfectly aligned with the horizon, and zoomed in a bit, will record what you do, just as on my sketch. All you have to do is to shout the comments to the camera about what you are doing or registering, for instance “separation starts!” , “full stall!” or “maximum lift!”. You will automatically move your hands towards the CP of the panel (batten) to reduce twist-forces needed to hold the angle of attack.

You can then shift quickly between the three test panels, several times, and thus, hopefully find which is the most or least powerful.

Back home again the video can be replayed and frozen as you hear your comments. Then the battens’ angle of incidence can be measured, in addition to the CP (position of your hands) on the battens.

I believe this cruder setup will give just as useful and interesting data as the more elaborate setup would do.

What have I missed?

Cheers,
Arne

Ash

Wow!

You mention hiring an anemometer.  I would guess that if you asked the Committee they might look kindly on buying an anemometer and taking it on as Association property.  Just a suggestion, but based on no knowledge about type, specification and cost. 

Jonathan  

2nd - yes you have to go with "the art of the possible".

4th - no, it's not the same as the third. Suppose you put on a cambered panel back to front. It would generate most of its force near the leech, giving an excellent pull on your bucket. But if that sail panel were on a boat, that pull would be mostly backwards (drag). What we are trying to achieve is maximising the lift (vertical, in these test panels, or perpendicular to the wind) and minimising the drag (horizontal, in the direction of the wind). If you don't measure both, you don't know how good the panel really is.

5th - will do.